Opponents of Central Maine Power's so-called "smart meters" say the devices are a health risk and an invasion of privacy, and that customers shouldn't have to pay to opt out.

CMP says smart meters are safe, cut energy use and allow utilities to quickly pinpoint problems during power outages.

Arguments were made Thursday to the state Supreme Court, which is being asked to reopen the proceedings.

Several justices were openly skeptical of the Public Utilities Commission's decision not to address the health and safety of the wireless-enabled meters. A lawyer for the commission said the opt-out should've addressed concerns.

The PUC allows CMP customers to keep a conventional meter at a cost of $12 a month, but it dismissed the complaint raising concerns about safety, privacy and other issues.